Semaphore.



No. 817,603. PATENTED APR. 10, 1906.

c. H. WILLIAMS.

SEMAPHORE. APPLIoATmN rum) No.1, 1905.

NITED STATES PATENT OFFICE.,

SEIVIAPHORE.

Specification of Letters Patent.

Patented April 10, 1906.

Application filed December l, 1905. Serial No. 289,742.

T0 a/ZZ whom it may concern.'

Be it known that I, CHARLES H. WILLIAMS, a citizen of the United States,residing in Milton, lin the county of Norfolk and State ofMassachusetts, have invented a new and useful Improvement in Semaphores,ofv which the following is a speciiication.

This invention relates particularly to that class of semaphores in whichlights of different colors are exhibited-such as red, green, and yellow,or colored and uncolored lightsthe object usually being, especially ifthe semaphore is used in connection with a railway, to indicate safety,caution,77 or danger to an approaching train.

In semaphores as commonly constructed the lantern is provided with alens, behind which is a light, and a' swinging arm is furnished providedwith one or more roundelsthat is to say, glass disks with plane surfaceson both sides. Swinging a roundel of a particular color in front ofthelens ofthe lantern indicates dangerj safety, or caution, as the case maybe.

In the present improvement I combine with the lantern provided with afocalizing or concentrating lens a swinging arm or casting, which isprovided with a series of lenses in place of the roundels previouslyused. By this means a lens in the arm or casting can be swung in irontof and at a suitable distance from the lens in the lantern, whereby thefocalizing is partly produced by the lens in the lantern and partly bythe lens in the semaphore arm or casting. Hence it is possible toconstruct the lenses of less thickness and better shape than those nowin use and make them of size and shape to iit the castings now in actualservice. The lens in the lantern is made of uncolored glass andispreferably concavo-convex, and the lenses in the semaphore-casting maybe made of red, green, and yellow glass, or red, green, and uncoloredglass, or of any desired combination of colors. I prefer concavo-conveXor plano-convex lenses for use in the semaphore arm or casting; but anysuitable form of focaliZing-lens may be employed.

As many castings now in use are constructed for roundels of greaterdiameter than the diameter of the lens in the lantern, I prefer toprovide lenses for the castings which are of a particular form designedfor this purpose, such form consisting of a central plano-conveX,concavo-conveX, or double-convex portion surrounded by an annular flangeor rim,

plane on both surfaces like a section of a roundel, integral with thelens proper an'd of suIicient diameter to iit the castings now in use.The central portion of the lens or the lens proper has a greaterdiameter than that of the lens in the lantern, and hence a largerilluminated area can be obtained than is the case with semaphores now inuse. The lenses may be placed with their convex surfaces toward or fromthe lantern, as desired.

The nature of my invention is fully described below, and illustrated inthe accompanyin'g drawings, in which- Figure 1 is a front elevation of asuiiicient portion of a semaphore to illustrate my invention. Fig. 2 isa section of the same taken on line 2 2, Fig. 1. Figs. 3, 4, and 5 aresimilar sections showing slight modifications of the invention.

Similar letters of reference indicate corresponding parts.

a represents the post of a semaphore, and l) the arm which carries theday-signals, said arm extending from a socket c, rigid with a hub orrotating frame d, pivoted to the front side of the post at e, allconstructed substantially in the ordinary manner.

g represents the case of the lantern, constructed substantially as usualand provided with a focalizing lens h, preferably concavoconvex, ofuncolored glass.

c is a curved arm integral with the hub d by means of the connections Z,said .arm k, connections Z, hub d, and socket c being preferably of asingle casting.

Supported in the arm c are a series of lenses m n p set in a line whichis in the arc of a circle whose center is at e and at a distance fromsaid center which is equal to the distance of the lantern-lens htherefrom. These lenses may be of diiferent colors or two of them may beof different colors and one uncolor-ed, as indicated in the drawings, inwhich m represents a red lens, n a green lens, and p an uncolored lens,indicating, respectively, danger, caution, and safety. The arrnc islocated at asuitable distance from the lanternlens h to obtain the bestresults from -the focalizing of the lantern-lens and the focalizing ofthe lens in the arm lc, which is swung in front of the lantern-lens, andby suitably arranging said lenses with relation to each other they canbe of less thickness than would be the case if the whole focalizing ofthe light were done by the lens in the lantern in connection with aroundel in the sema- IOO IIO

phore-casting. All theselenses are surrounded by similar annular flangesor rims s plane on both surfaces, the flanges or rims and the lenses orcentral portions m, n, and p being in each case integral andconstituting practically a single lens which is of greater diameter thanthe lantern-lens h and which will iit in a casting or arm constructedoriginally to receive roundels, which are generally made larger indiameter than the lantern-lens.

Referring to Figs, l and 2, it will be seen that the lenses m, n, and 7)are concave-convex. It is not necessary, however, that they should beconcave-convex, as they may be plano convex, as indicated in Fig. 4, ordouble-convex, as indicated in Fig. 5. Of course it is always necessarythat one surface should be convex; otherwise it would not be afocalizing-lens. Moreover, it is not essential that the convex surfaceof the lens should face the lantern-lens, as illustrated in Figs. l and2, as the lens may be so disposed that the convex-surface will befarther from the lantern-lens, as illustrated in Fig. 3. I prefer,however, that the lens, whether placed with its concave 'or convex sidetoward the lantern-lens, should be concave-convex or planoconvex.

All the lenses employed in this invention or improvement have smoothsurfaces without concentric shoulders or grooves, thus avoiding shadowsand reducing the danger of the collection of dust and dirtto a minimumand enabling the lenses to be easily cleaned.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. In a semaphore, a lantern having a lens of only partial concentratingpower, and two or more supplementary lenses with means to bring themsuccessively in front of said lantern-lens, said lenses being also ofpartial concentrating power, whereby, by the combined action of thelantern-lens and the supplementary lens, the lantern-rays are properlyfocalized, substantially as specified.

2. In a semaphore, a'lantern having a lens with one convex face, and apivoted radiusarm mounted to swing in front of said lens, in which aremounted two or more lenses adapted to come in succession before thelantern-lens by the swinging of the radius-arm, said radius-arm lensesbeing of a curvature such as to supplement the lantern-lens in properlyfocalizing the illuminating rays from the lantern, substantially asspecified.

3. In a semaphore, a lantern having a lens of only partial concentratingpower, and`a l semaphore-arm in which are mounted two or more lensesalso of partial concentrating power, adapted to be brought by themovement of said arm successively in front of said. lantern-lens andcooperate with the latter to properly focalize the lantern-rays, saidsupplementary lenses being of larger diameter than that of thelantern-lens, substantially as specified.

4. In a semaphore, a lantern-lens of partial condensing power and two ormore supplementary lenses also of partial condensing power, mounted tocome in succession before said lantern-lens, at a suitable distancetherefrom to coperate with the latter in properly focalizing thelantern-rays, substantially as specified.

5. In a semaphore, in combination with the lantern and lens thereof; asignal-arm, and lenses secured therein and thereby adapted to be swungup in front of the lanternlens, said signal-lenses consisting of acentral lens-shaped portion and an annular fiange or rim plane on bothsurfaces or sidesxand integral with the said central portion, wherebythe light may be focused partly by the lantern-lens and partly by thesignal-lens.

6. In a semaphore, in combination with the lantern and lens thereof, asignal-arm, and lenses having one convex surface and secured therein andthereby adapted to be swung up in front of the lantern-lens, said signal-lenses consisting of a central lensshaped portion and an annular flangeor rim plane on both surfaces or sides and integral with the saidcentral portion, whereby the light may be focused partly by thelanternlens and partly by the signal-lens.

7. In a semaphore, in combination with the lantern and lens thereof, asignal-arm, and concave-convex lenses secured therein and therebyadapted to be swung up in front of the lantern-lens, said signal-lensconsisting of a central lens-shaped portion and an annular flange or rimplane on both surfaces or sides and integral with the said centralportion, whereby the light may be focused partly by the lantern andpartly by the signal-lens.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES H. WILLIAMS.

Vitnesses y HENRY W. VVILLIAMs, I A. K. Hoon.

IOG

